1. Field of the Invention
The present invention relates to a receiver having Inphase-Quadrature (I-Q) imbalance compensation and an I-Q imbalance compensation method thereof. More particularly, the present invention relates to a receiver having I-Q imbalance compensation and an I-Q imbalance compensation method thereof that feature a low computational complexity and a short latency.
2. Descriptions of the Related Art
In response to modern people's desires for high-speed wireless transmission, wireless communication systems incapable of high-speed transmission have been gradually rejected in the market and, naturally, having a high-speed transmission function has become an essential requirement on future wireless communication systems. For the purpose of high-speed wireless transmission, oscillating frequencies of radio-frequency (RF) oscillators must be increased correspondingly. However, as the oscillating frequencies of the RF oscillators increase, the Inphase-Quadrature (I-Q) imbalance effect of the oscillators also becomes more serious.
The so-called I-Q imbalance refers to a phenomenon that an imbalance in amplitude and/or in phase exists between the I-Q channels. Because the I-Q imbalance would seriously affect the performances of wireless communication systems, it is difficult for a wireless communication system without I-Q imbalance compensation to provide desirable communication quality.
Conventional I-Q imbalance compensation methods are generally divided into the following two categories:
(1) methods that accomplish the detection and the compensation by use of known time-domain or frequency-domain preamble signals or pilot signals; and
(2) methods that accomplish the compensation by use of a time-domain filter.
However, the methods of the first category are known to have a great computational complexity, which tends to cause a large amount of hardware resource waste; and the methods of the second category are known to have a long latency, which tends to cause a long waiting time.
Accordingly, an urgent need exists in the art to provide an I-Q imbalance compensation method that features a low computational complexity and a short latency to compensate the I-Q imbalance effect incurred in the existing wireless communication systems that pursue high-speed wireless transmission.